To use pop-up menus in the source view, select text or position your
  mouse pointer in the source view, and press MB3.  The debugger inserts
  the selected text or line number in the menu items of the pop-up menu.

  If you press MB3 while your mouse pointer rests on a source line in the
  source view, a pop-up menu with the following items appears:

  Examine [selection]    Evaluates the selected expression and prints
                         its value in the command view.

  Monitor [selection]    Inserts the selected expression in the monitor
                         list of the monitor view.

  Deposit [selection]    Provides the Assign/Deposit dialog box.

  Break on Routine       Sets a breakpoint on a selected routine name.
    [selection]

  Toggle Breakpoint      Activates/deactivates breakpoint at mouse pointer.
    at Line
    [line number]

  Temporary Breakpoint   Sets temporary breakpoint at mouse pointer.
    at Line
    [line number]

  Go to Line             Branches to [line number] without executing source
    [line number]        code betwen the line at which execution is suspended
                         and [line number].

  Display Instruction    Displays decoded instruction stream of your program.

  Step                   Step to next line, stepping over routine calls.

  Go                     Resume execution of program.

  If you press MB3 while your mouse pointer rests in the annotation area
  of the source view, a pop-up menu with the following items appears:

  Toggle Breakpoint      Activates/deactivates breakpoint at mouse pointer.
    at Line
    [line number]

  Temporary Breakpoint   Sets temporary breakpoint at mouse pointer.
    at Line
    [line number]

  Go to Line             Executes until [line number] is reached.
    [line number]

  Step                   Step to next line, stepping over routine calls.

  Go                     Resume execution of program.